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APPLY(1) DragonFly General Commands Manual APPLY(1)

NAME

apply -- apply a command to a set of arguments

SYNOPSIS

apply [-ac] [-d] [-#] commandargument...

DESCRIPTION

The apply utility runs the named command on each argument argument in
turn.
Character sequences of the form ``%d'' in command, where `d' is a digit
from 1 to 9, are replaced by the d'th following unused argument. In this
case, the largest digit number of arguments are discarded for each
execution of command.
The options are as follows:
-# Normally arguments are taken singly; the optional number -#
specifies the number of arguments to be passed to command. If
the number is zero, command is run, without arguments, once for
each argument.
If any sequences of ``%d'' occur in command, the -# option is
ignored.
-ac The use of the character `%' as a magic character may be changed
with the -a option.
-d Display the commands that would have been executed, but do not
actually execute them.

ENVIRONMENT

The following environment variable affects the execution of apply:
SHELL Pathname of shell to use. If this variable is not defined, the
Bourne shell is used.

HISTORY

The apply command appeared in 4.2BSD.

AUTHORS

Rob Pike

BUGS

Shell metacharacters in command may have bizarre effects; it is best to
enclose complicated commands in single quotes ('').
The apply utility does not recognize multibyte characters.
DragonFly 4.9 December 13, 2006 DragonFly 4.9
apply(n) Tcl Built-In Commands apply(n)
______________________________________________________________________________

NAME

apply - Apply an anonymous function

SYNOPSIS

DESCRIPTION

The command apply applies the function func to the arguments arg1arg2... and returns the result.
The function func is a two element list {argsbody} or a three element
list {argsbodynamespace} (as if the list command had been used). The
first element args specifies the formal arguments to func. The
specification of the formal arguments args is shared with the proc
command, and is described in detail in the corresponding manual page.
The contents of body are executed by the Tcl interpreter after the
local variables corresponding to the formal arguments are given the
values of the actual parameters arg1arg2.... When body is being
executed, variable names normally refer to local variables, which are
created automatically when referenced and deleted when apply returns.
One local variable is automatically created for each of the function's
arguments. Global variables can only be accessed by invoking the
global command or the upvar command. Namespace variables can only be
accessed by invoking the variable command or the upvar command.
The invocation of apply adds a call frame to Tcl's evaluation stack
(the stack of frames accessed via uplevel). The execution of body
proceeds in this call frame, in the namespace given by namespace or in
the global namespace if none was specified. If given, namespace is
interpreted relative to the global namespace even if its name does not
start with "::".
The semantics of apply can also be described by:
proc apply {fun args} {
set len [llength $fun]
if {($len < 2) || ($len > 3)} {
error "can't interpret \"$fun\" as anonymous function"
}
lassign $fun argList body ns
set name ::$ns::[getGloballyUniqueName]
set body0 {
rename [lindex [info level 0] 0] {}
}
proc $name $argList ${body0}$body
set code [catch {uplevel 1 $name $args} res opt]
return -options $opt $res
}